Answer: B) Must have.
Explanation for this question is being written.
Answer: A) Must have been.
Answer: C) Expresses certainty about the past.
Answer: C) Can't have.
Answer: B) He must have studied English.
Answer: B) To express a past certainty.
Answer: A) Must have left.
Answer: B) Must have left.
Answer: A) Must have.
Answer: B) Can't have finished.
Answer: A) They must not have received the message.
Answer: D) Johny must have used his smartphone in the exam as he finished it in just 5 minutes.
Answer: D) Must have.
Answer: B) Must have been.
Answer: A) Could
Answer: A) Must have studied.
Answer: A) Must have affected.
Answer: A) Were meant to.
Answer: C) Cannot have lost.
Answer: D) Must have experienced.
Answer: C) We are 100% sure.
Answer: C) Must have.
Answer: A) TRUE
Answer: B) Have left.
Answer: D) Probably will not have found.
Answer: C) Must have been working.
Answer: A) Must have eaten.
Answer: E) Must have been.
Answer: B) Can't have been.
Answer: B) The price must not have been acceptable.
Answer: A) Can't have killed.
Answer: D) She thinks Roland must have forgotten to pay.
Answer: E) Must have lost.
Answer: A) It must have been very expensive.
Answer: B) Can't have seen.
Answer: C) He must have forgotten about the meeting.
Answer: B) Must have gone.
Answer: C) Speculation
Answer: A) Must have forgotten.
Answer: B) Must have forgotten.
Answer: C) Must have taken.
Answer: A) Must have seen.
Answer: D) Must have passed.
Answer: C) Must have studied.
Answer: D) Can't have gone.
Answer: A) It is certain.
Answer: C) We are sure about something.
Answer: A) Would taste / had used.
Answer: C) Must have slept.